Electronic devices that are intended to come into contact with users need to be kept clean and sanitized. A typical such device is a telephone handset, which is intended to come into contact with users' hands and ears and into very close proximity to users' mouths. When dirty, the device could simply be discarded, but that is cost-prohibitive. Wiping down the device often does not clean the device sufficiently well. Washing-off the dirt usually cannot be done effectively because it would damage the electronics.
Some electronic devices are adapted for use in water, such as submersible portable telephones and “shower” radios. However, the cost involved in making these devices water-proof is high. Furthermore, the water-proofing often interferes with the device's operation. For example, the water-proofing of the telephone and radio interfere with and degrade their audio quality.
The WhisperPhone headset is “dishwasher-safe”. However, it is a strictly-acoustical device that provides feedback of the user's speech to the user's ear, and has no electronics that could be damaged by water.